Anatomical distribution of cocaine- and amphetamine-regulated transcript (CART) peptide in the human spinal cord

The cocaine- and amphetamine-regulated transcript (CART) peptide, a neuropeptide highly expressed in the central nervous system, is involved in various physiological processes, including pain modulation, reward, learning, and memory. While previous studies have examined the distribution of CART peptides in the rat and human brain, no data exist on their distribution in the human spinal cord. Therefore, we investigated the localization of CART peptides in the human spinal cord using immunohistochemistry. Our analysis revealed dense CART-immunoreactive fibers and varicosities in the anterior, lateral, and dorsal funiculi of the white matter along the entire spinal cord. CART-immunoreactive neurons were identified in the Rexed’s laminae (strong immunoreactivity in laminae I-II and IX, and moderate immunoreactivity in laminae III-VIII and X. Strong CART immunoreactivity was observed in the dorsal (Clarke), intermediolateral and sacral parasympathetic nuclei, and moderate in the internal basilar, lateral spinal and lateral cervical, central cervical, and lumbar and sacral precerebellar nuclei. The widespread but regionally varied immunoreactivity suggests a potential role for CART in modulating spinal cord functions, including pain processing, autonomic regulation, and motor control.